UAS Integration in the NAS ASCI 638 - 3.6

 

Figure 1. UAS in the NAS (Cameron, 2012)

“NextGen is the FAA-led modernization of our nation’s air transportation system” (What is NextGen, 2017).  The goal is to increase safety and efficiency in the national airspace. Replacing ground based navaids, such as an NDB or VOR, with GPS based airways. Radar would be replaced with Satellite GPS tracking and Automatic Dependent Surveillance-Broadcast (ADS-B) of aircraft for ATC. These combined will enable aircraft to fly closer together, yet still safely, since the location is more accurate and up to date compared to radar. More direct routes are able to be taken with GPS than ground based navaids which decreases fuel consumption, brings down the overall cost of the trip and reduces transportation time (What is NextGen, 2017).  

ATC needs to be able to communicate with the UAS controller whenever the UAS is in controlled airspace.  Since the UAS controller is on the ground, and most likely not in line-of-sight communication with ATC the UAS could be used to relay the communication to the ground controller via satellite communications (Pongracz & Palik, 2012).  This would allow direct communication with the UAS controller and it would be similar to contacting an onboard pilot. Of course, this only works for larger UASs, most notable military controlled UASs that have access to satellite communications.  An example would be the Global Hawk that uses Satcom to relay UHF/VHF communication between ATC and the ground controller (Global Hawk UAS, 2018).

According to the Federal Aviation Regulation (FAR) 14CFR 91.111(b) “the operator of an aircraft must maintain vigilance so as to see and avoid other aircraft. The operator must also give way to other aircraft if they have the right of way”.  Since a UAS cannot see to avoid it needs to “sense and avoid”.  ADS-B is used to broadcast to ATC the position, altitude and velocity of an aircraft. Having ADS-B built into a UAS would enable ATC to locate the UAS, any aircraft or person with an ADS-B receiver and let the UAS know of other aircraft in its vicinity and it could navigate to stay clear of the manned aircraft. A company called UASioni has released a line of small ADS-Bs that could easily be fitted into a small UAS, some of these are only an inch by an inch in size (ADS-B Transceivers, n.d.).  

PrecisionHawk has developed Low Altitude Tracking and Avoidance System, or LATAS. LATAS is “onboard system that provides flight planning, tracking and avoidance for every drone in the sky using real-time flight data transmission based on existing world-wide cellular networks” (Say Hello, 2015).  LATAS uses existing cell towers to transmit a UASs location to ATC, which would relay that position to pilots in the area. This is a small bit of electronics, about one inch by two inches, that can be added to any UAS during manufacturing.

NextGen will need to address human factors the same way the previous National Airspace system (OldGen? Maybe PreviousGen?) needed to. We will still have crew rest, human inattention, human mistakes, a need for well designed human machine interface and crew resource management just to name a few. With the advent of ADS-B receivers there has been an advancement in safety. Previously a pilot needed to be visually scanning outside the cockpit when flying VFR, and even IFR at times if not in the clouds, in order to see-and-avoid other aircraft. While this is still a necessity the use of ADS-B has enabled pilots to be able to see other aircraft relative to their position on a moving map or digital display in today’s glass cockpits. If a UAS had an ADS-B transmitting it location even a small hard to visually see UAS will be prominently displayed on a screen for other pilots in the area.

When we fully upgrade to NextGen, or if everyone starts using ADS-B while still fying ground based navaids human factors will always be an issue. We need to continue to train, improve and stay vigilant as members of the aviation industry. As with all aviation it takes skilled people, on the ground, in the tower or in the sky to make it all work safely. 

  

References

ADS-B Transceivers, Receivers and Navigation Systems for Drones (n.d.). Retrieved January 28, 2018 from http://www.unmannedsystemstechnology.com/company/UASionix-corporation/

Cameron, A. (2012, May 22). The System: Fly the Pilotless Skies: UAS and UAV. Retrieved January 28, 2018, from http://gpsworld.com/the-system-fly-the-pilotless-skies-uas-and-uav/

Say Hello to LATAS (January 09, 2015). Retrieved January 28, 2018 from http://www.precisionhawk.com/media/topic/say-hello-to-latas/

Global Hawk UAS of NASA. (2018). Retrieved January 28, 2018, from https://directory.eoportal.org/web/eoportal/airborne-sensors/content/-/article/global-hawk

What is NextGen? (2017, November 21). Retrieved January 28, 2018, from https://www.faa.gov/nextgen/what_is_nextgen/